Big Ideas Math: Modeling Real Life, Grade 6
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3. Solving Equations Using Multiplication or Division
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Exercise 3 Page 263

Use the Subtraction Property of Equality to eliminate the addition.

p=5/8

Practice makes perfect
To solve the equation, we have to isolate p on one side. Using the Subtraction Property of Equality we will subtract 14 from both sides of the equation. This will eliminate addition and isolate p.
7/8=1/4+p
7/8-1/4=1/4-1/4+p
7/8-1/4=p
7/8-1* 2/4* 2=p
7/8-2/8=p
7-2/8=p
5/8=p
p=5/8
To check that this solution is correct, let's substitute p= 58 into the original equation and simplify.
7/8=1/4+p
7/8? =1/4+ 5/8
7/8? =1* 2/4* 2+5/8
7/8? =2/8+5/8
7/8? =2+5/8
7/8=7/8 âś“
Since the left-hand side and right-hand side are equal, p= 58 is the correct solution.

Extra

Properties of Equality

There are four main Properties of Equality that we use when solving linear equations.

Properties of Equality
Addition Property of Equality If a=b, then a+c=b+c.
Subtraction Property of Equality If a=b, then a-c=b-c.
Multiplication Property of Equality If a=b, then ac=bc.
Division Property of Equality If a=b and c is not 0, then a/c=b/c.

In later chapters, you will learn about some more advanced Properties of Equality. As an example, there is a property for when we need to eliminate a radical or an exponent.

Power Property of Equality

If a=b, then a^m=b^m.